PROJECT SUMMARY/ABSTRACT Hypoglycemia and hyperglycemia are common and morbid problems for end stage kidney disease patients treated with dialysis. Severe hypoglycemia occurs frequently among dialysis patients with and without diabetes due to reduced kidney gluconeogenesis, protein-energy wasting, a blunted counter-regulatory response, and reduced medication clearance and may cause substantial morbidity due to accidents, arrhythmias, and cardiovascular events. However, accurate rates of hypoglycemia (including subclinical episodes), hypoglycemia risk factors, and associations of hypoglycemia with clinical outcomes are not known in the dialysis population. Conversely, hyperglycemia due to inadequately treated diabetes may promote painful peripheral neuropathy, vision-threatening retinopathy, and infections, but standard measures of glycemia such as hemoglobin A1c are known to be unreliable among dialysis patients, leading to diagnostic and therapeutic nihilism. The goal of this research project is to comprehensively define glycemia in dialysis patients using modern continuous glucose monitoring (CGM) technology, informing needs for clinical care and building a foundation for intervention studies. CGM offers a new paradigm for glycemia assessment and management that can provide new scientific insights and potentially change the clinical approach to glycemic management. However, there has been no large, externally valid study to understand the incidence or severity of abnormalities detectable by CGM, identify which patients may benefit most from use of CGM, or examine whether CGM metrics are related to clinically relevant outcomes in this population. We propose a prospective community-based cohort study of 800 patients treated with dialysis at Northwest Kidney Centers, a not-for- profit organization that provides the majority of dialysis care in the greater Seattle metropolitan area. The foundation of the cohort study will be a 10-day period of CGM, performed at baseline using cutting-edge technology. A participatory approach to research will enhance enrollment, external validity, and clinical relevance. With this cohort, we aim to (1) determine the incidence and severity of hypoglycemia and its clinical risk factors among dialysis patients with and without diabetes; (2) define the distribution and clinical correlates of glucose time in range and related CGM metrics among dialysis patients with diabetes; and (3) test associations of hypoglycemia and time in range with clinical outcomes relevant to dialysis patients. Results may suggest opportunities for CGM implementation to improve clinical care and will define appropriate populations, interventions, outcomes, and power assumptions for clinical trials.